They are divided into two parts separated by a single space. Those two parts are the outward code and the inward code. The Blaenau Gwent outward code includes the postcode area and the postcode Willowtown district. The inward code includes the postcode sector and the postcode unit.

If you want to send a mail to Willowtown, you should use the corresponding Postcode. Willowtown Postcode district is NP23 6.